Levigating-mill.



No. 776,472. v PA'L'ENTED NOV. 29, 1904. J. W. H. JAMES.

LEVIGATING MILL.

APPLIOATION FILED MAY 21. 1902.

No MoDBL. a SHEETS-SHEET 1.

["hllll www" l l l 'will PATENTED NOV. 29, 1904.

J. W. H. JAMES.

LEVIGATING MILL.

APPLIGATION FILED MAY 21. 1002.

2 SHEETS-SHEET 2.

NU MODEL.

it: l

lJNiTnn STATES Patented November 29, 1904.

l nTnNT Trice.

LEVlGATlNG-WIILL.

SPECIFICATION forming part of Letters Patent No. 77 6,472, datedNovember 29, 1904.

i Application filed May 21, 1902. Serial No. 108,386. (No model.)

To if/ZZ whom t may concern:

Be it known that 1, J oHN W. H. J Aires, a subject of the King of GreatBritain and 1reland, and a resident of Philadelphia, Pennsylvania, haveinvented certain Improvements in Levigating-Mills, of which thefollowing is a speciiication.

My invention consists of certain improvements in levigatin'g-mills ofthat type in' which 4rotating grinding-blocks act in conjunction with aiiXed grinding-block at the bottom of a tub or tank containing water,the grinding' operation being thereby eifected under water and theiinely-ground material rising to the surface, whence it loats into asettling-tank.

The objects of my invention are to so construct such a levigating-millas to readily control the relative position of the fixed and movablestones or grinding-surfaces, to provide a positive current for carryingthe finely-ground 'material to the surface of the water in thegrinding-tub, to permit ready removal of unground material accumulatingin the bottom of the tub, to prevent accumulations of material upon thetops of the movable grindingsurfaces, and generally to so improve theconstruction and operation of the mill as to render the same moreacceptable than such mills mills as heretofore constructed.

In the accompanying draw-ings, Figure 1 is a view, partly in elevationand partly in longitudinal section, of a levigating-mill constructed inaccordance with my invention. Fig. 2 is a sectional plan view on theline a, a, Fig. 1; and Fig. 3 is a detached sectional View of part ofthe mill.

On a suitable bed or foundation 1 is erected a structure 2, upon whichis supported the grinding tub or tank 3, the latter being. composed, bypreference, of an outer metallic shell with wooden lining` and having atthe bottom a iiXed grindstone 4, the central opening' or eye of thisstone being in the present instance occupied by a casing 5, containing'a chamber 6, the top of the casing 5 being perforated and having acentral step-bearing 7 for the rotating vertical shaft 8 of the mill.The upper portion of this shaft is adapted to a bearing 9 in a structure10, which is supparted above the grinding-tub upon posts or columns 11,this upper structure having a counter-shaft 1Q., which receives thedrivingbelt, and said counter-shaft being provided with a bevel-pinion13, which meshes with al bevel-wheel 14, engaging the upper end of theshaft 8, so as to turn the same, the connection being by means of asquared or splined construction of the shaft, so as to permit verticalmovement of the latter without deranging the driving connection betweenthe same and the bevel-wlieel 14.

Secured to the shaft 8 is a hub 15, with a number of projecting arms 16,three of which are shown in the present instance, and to the outer endof each of these arms is securely bolted another arm, 17 which issecured to one of the rotating grinding-stones 18 of the mill. Byraising and lowering the shaft 8', therefore, the vertical positionA ofthe stones 18 in respect to the fixed base-stone et can be regulated andthe mill thus readily adapted to the conditions under which the grindingcan best be effected, the adjustment also providing a means forcompensating for the wear of the grinding-stones.

In order to effect the vertical adjustment of the shaft 8 and its stones18, I mount upon the said shaft a sleeve 19, which engages with suitablecollars on the shaft, as shown in Fig. 3, so that the latter is free toturn in the sleeve, but must partake of any vertical movement impartedto the `latter, such vertical movement being effected by means of ahand-wheel 20, mounted on the structure 1() and engaging with thethreaded portion of a rod 21, which is connected to a yoked or forkedlever 22, the latter engaging with projections on the sleeve 19 andbeing fulcrunied upon a bolt 23, which depends from the structure 10, asshown in Fig. 1. The adjusting devices are therefore readily accessible,and the inconvenience arising from the use of an adjusting device actingupon the lower end of the shaft is eifectually overcome, a fixedstep-bearing being provided for the lower end of said shaft, whichbearing is not likely to get out of order and require attention. Henceits comparative inaccessibility is no objection.

The centrifugal action duc to the rotating stones 18 causes the water toflow from the IOO central portion of the tub to the outer portion of thesame and to rise in such outer portion, and the current thus created hasa natural tendency to cause the linely-ground particles of material torise to the surface of the water; but in order to render this upwardcurrent in the outer portion of the tub more positive and certain in itsaction l mount in a bearing upon each of the arms 17 and in a bracket 24thereon a short vertical shaft carrying afan or screw 25 and aspur-wheel 26, and on the lining of the tub 3 I mount an annular rack27, meshing with said spur-wheels 26, whereby as the arms 17 are rotatedrotating' movement will be imparted to the fans 25, the blades of whichare so set as to cause the water acted on thereby to rise in the tub.Not only is the flow of the powdered material to the surface of thewater in the tub assisted by this action, but the increased force of thecurrent owing over the tops of the stones 18 tends to prevent theaccumulation thereon of material which is too heavy to be carried off bya cui'- rent due solely to centrifugal action. Hence the operation ofthe mill is improved in this respect. ln all mills of this class,however, heavy particles have a tendency to collect upon the centralportion of the bottom of the tub within the annular path traversed bythe stones 18, and in order to provide for the ready discharge of suchaccumulations I mount upon the perforated top of the casing 5, whichoccupies the eye of the xed lower stone, a perforated valve or damperplate 28, which when adjusted so that its openings register with vthosein the top of the casing will permit the accumulated material in thebottom of the tub to pass into the chamber 6 within the casing 5, fromwhich after closing the valve 28 it can be discharged by opening thevalve 29, which normally closes the lower end of said casing, thegrinding-tub being thus freed of these accumulations without any wasteof the water. The accumulations thus discharged from the chamber 6 fallinto a pit 30 beneath the tub, which pit is filled with water andcommunicates through a pipe 3l with a well 32, which also receives theoverflow from the settling-tank 33 of the mill, a pump 34 returning thewater from the well 32 to the grinding-tub 3 through pipes 35 and 36.

The pipe 37, which carries the overflow from the grinding-tub to thesettling-tank 33, communicates with the upper portion of saidsettling-tank, and in this portion of the latter is a series oftransverse halide-plates 38, so that the finely-powdered materialcarried off from the grinding-tub by the overow will in its passageacross the settling-tank toward the overflow-pipe 39 of the latter comeinto contact with these baille-plates and will be arrested thereby andcaused to drop into the lower portion of the tank, the accumulationstherein being removed at intervals by opening a valve 40 and beingthereby permitted to drop into a conveyer 11, whereby they are carriedtothe point at which they are to be used or further treated.

The mill forming the subject of my invention has been designedespecially for grinding lead carbonate in the manufacture of paint; butthe invention is applicable to mills for grinding' any material in whichthe lighter particles are separated from the heavier particles by reasonof the greater influence eX- erted upon them by the ascending currentsof water in the grinding-tub. The opening and closing of the valve ordamper plate 28 can be effected at the required intervals by means of ahooked rod or other suitable implement engaging the same and manipulatedby the attendant.

Having thus described my invention, I claim and desire to secure byLetters PatentH l. The combination, in a levigating-mill, of thegrinding-tub and its fixed stone, having a downwardly-delivering centraldischarge-ori- Jdce, a valve for closing the outlet therefrom, themovable stones, the rotating shaft carrying the same, a sleeve engaging'said shaft so as to be capable of lifting the same, and mechanism abovethe tub for raising and lowering said sleeve, substantially asspecified.

2. The combination, in a levigating-mill, of the gi'inding-tub and itsXed stone, the rotating structure carrying' stones which have nooperative movement other than that around the vcentral axis of the mill,fans mounted upon the said rotating' structure, and means for rotatingsaid fans so as to cause them to induce an upward current in the outerportion of the tub, substantially as specified.

3. The combination, in a levigating-mill, of the grinding-tub, therotating stones, the fixed stone having in its central portion or eye, acasing nclosing a chamber with valved opening at the bottom of the same,and a valve or damper whereby matter accumulating in the central portionof the tub may be permitted to enter said chamber at intervals,substantially as specified.

4. The combination, in a levigating-mill, of the grinding-tub, thesettling-tank receiving the overiow from the tub, a well receiving theoverflow from the settling-tank, a pit in connection with said well andreceiving material discharged from the grinding-tub independently of theoverflow, and a circulating device for returning' the water from saidwell to the grinding-tub, substantially as described.

In testimony whereof l have signed my name to this specification in thepresence of two subscribing witnesses.

JOHNA W. H. JAMES.

Vitnesses:

F. E. BEcH'roLD, J os. H. KLEIN.

IOO

IIO

IIS

